ULJIN, South Korea-- Police and fire officials conducted a probe Wednesday at an east coast mountain site believed to be the ignition point of a recent major wildfire.

The wildfire, which started in Uljin, 330 kilometers southeast of Seoul, on March 4, became the country's most devastating on record as it spread to nearby areas in the eastern province of Gangwon, wiping out 643 facilities and scorching an estimated 20,923 hectares of woodland.

Officials from the police, the National Forensic Service and the Korea Forest Service (KFS) conducted a joint probe at the purported ignition site, taking photos and collecting various evidence.

Authorities believe the blaze may have started due to a cigarette butt thrown from a passing vehicle, as the fire was kindled near a road, according to CCTV footage.

The KFS and police have identified the owners of four vehicles that passed through the area close to the time when the fire broke and also obtained black boxes from the vehicles in question. Officials said they plan to further the investigation based on the collected evidence and results of their forensic analysis.

Source: Yonhap News Agency